Description:
<jats:title>Abstract</jats:title><jats:p>Cyclohexene and formic acid have been copolymerized to an unsaturated polyester by a free‐radical‐initiated, step‐growth polymerization process. The polymerization system contains iodine and a hydroperoxide in addition to the cyclohexene and formic acid. No polymerization occurs if any one of these components is omitted. The polymerization process is rapid, and polymer yields as high as 95% have been obtained in less than 1 hr. The polymer is an unsaturated polyester and appears to be poly(oxy‐2‐cyclohexen‐1,4‐enylcarbonyl). A step‐growth polymerization mechanism involving formic acid radicals, iodine atoms, and cyclohexene allylic hydrogen atom abstraction has been proposed for this reaction.</jats:p>